libfido2: make test more robust (#54070)
libfido2: make test more robust (#54070)

The test would fail if no USB devices are present, like within
a docker container on Linux. The Logic has been slightly changed
so that it does not fail anymore.

See:
https://github.com/Homebrew/linuxbrew-core/pull/20080#issuecomment-612706103
dsXLII/homebrew-core,Homebrew/homebrew-core,jvillard/homebrew-core,aabdnn/homebrew-core,zyedidia/homebrew-core,lemzwerg/homebrew-core,cblecker/homebrew-core,nandub/homebrew-core,mfikes/homebrew-core,jvillard/homebrew-core,dsXLII/homebrew-core,chrisfinazzo/homebrew-core,nbari/homebrew-core,lembacon/homebrew-core,nandub/homebrew-core,lembacon/homebrew-core,cblecker/homebrew-core,spaam/homebrew-core,nbari/homebrew-core,mfikes/homebrew-core,edporras/homebrew-core,uyjulian/homebrew-core,rwhogg/homebrew-core,Moisan/homebrew-core,stgraber/homebrew-core,spaam/homebrew-core,mbcoguno/homebrew-core,maxim-belkin/homebrew-core,JCount/homebrew-core,maxim-belkin/homebrew-core,uyjulian/homebrew-core,Homebrew/homebrew-core,adam-moss/homebrew-core,rwhogg/homebrew-core,chrisfinazzo/homebrew-core,sjackman/homebrew-core,jabenninghoff/homebrew-core,Moisan/homebrew-core,mbcoguno/homebrew-core,mahori/homebrew-core,mbcoguno/homebrew-core,zyedidia/homebrew-core,JCount/homebrew-core,stgraber/homebrew-core,lembacon/homebrew-core,jvillard/homebrew-core,jabenninghoff/homebrew-core,edporras/homebrew-core,sjackman/homebrew-core,mahori/homebrew-core,adam-moss/homebrew-core,filcab/homebrew-core,lemzwerg/homebrew-core,Linuxbrew/homebrew-core,Linuxbrew/homebrew-core,makigumo/homebrew-core,aabdnn/homebrew-core,makigumo/homebrew-core,filcab/homebrew-core